If you happen to be in one of the 25 countries where Google offers direct carrier billing on mobile phones, good news: you'll soon be able to buy apps, movies, music, books, and the like on your tablet and have it billed to your carrier...even on Wi-Fi tablets.

So, your tablet doesn't have to actually be set up on your mobile account, just your phone. Once everything is good to go on the phone side, it should work through your Google account, thus allowing purchases to me made on tablets and show up on your monthly phone bill.